Preliminary studies on selection indices for activating seedling growth in mangosteen (Garcinia mangostana L.)

Abstract

Studies on selection indices for activating seedling growth in mangosteen were conducted in the central orchard at the main campus of Kerala Agricultural University. The present investigation was undertaken with the main aim of identifying some of the basic reasons for slow growth in mangosteen, and to address this problem by developing and identifying criteria to select the age of the mother plant, fruit, seed and seedling characters or direct selection indices at all four stages with respect to seedling growth. Mother plants of four distinct age groups were used in the study. Variables were generated using all fruit, seed and seedling characters such as fruit index, seed index and seedling index by principal component analysis (PCA). Using PCA and multiple regression analysis, prediction model was fitted for the three indices.  Major fruit, seed and seedling characters were identified by stepwise regression. Hierarchial analysis was performed based on Euclidean distance to find the similarities between the four age groups. Discriminant function analysis was performed and six discriminant functions were fitted with corresponding D2 values to discriminate the six pairs involving the four age groups of the mother plants. For practical purposes, selection indices and best age group of mother plants are described in the work.